US7431871B2 - Method for regulating the contraction of molded parts - Google Patents

Method for regulating the contraction of molded parts Download PDF

Info

Publication number
US7431871B2
US7431871B2 US10/472,861 US47286103A US7431871B2 US 7431871 B2 US7431871 B2 US 7431871B2 US 47286103 A US47286103 A US 47286103A US 7431871 B2 US7431871 B2 US 7431871B2
Authority
US
United States
Prior art keywords
temperature
mold
cavity
pressure
end
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active, expires
Application number
US10/472,861
Other versions
US20040131715A1 (en
Inventor
Jürgen Frey
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Priamus System Technologies AG
Original Assignee
Priamus System Technologies AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to DE2001114228 priority Critical patent/DE10114228A1/en
Priority to DE10114228.5 priority
Application filed by Priamus System Technologies AG filed Critical Priamus System Technologies AG
Priority to PCT/EP2002/002844 priority patent/WO2002076704A1/en
Assigned to PRIAMUS SYSTEM TECHNOLOGIES AG reassignment PRIAMUS SYSTEM TECHNOLOGIES AG ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: FREY, JURGEN
Publication of US20040131715A1 publication Critical patent/US20040131715A1/en
Publication of US7431871B2 publication Critical patent/US7431871B2/en
Application granted granted Critical
Application status is Active legal-status Critical
Adjusted expiration legal-status Critical

Links

Images

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17Component parts, details or accessories; Auxiliary operations
    • B29C45/76Measuring, controlling or regulating
    • B29C45/78Measuring, controlling or regulating of temperature
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17Component parts, details or accessories; Auxiliary operations
    • B29C45/76Measuring, controlling or regulating
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17Component parts, details or accessories; Auxiliary operations
    • B29C45/76Measuring, controlling or regulating
    • B29C45/77Measuring, controlling or regulating of velocity or pressure of moulding material

Abstract

A method for regulating the contraction of molded parts in a cavity in a mold of an injection molding machine after completing the filling process of the cavity with molten mass. According to the method, the temperature of the mold is regulated, whereby the temperature and/or the internal pressure in the cavity is monitored and adapted to a reference curve by performing temperature equalization of the mold from the end of the filling phase or from a maximum pressure in the cavity until the end of the injection cycle.

Description

BACKGROUND OF THE INVENTION

The invention relates to a method for controlling the shrinkage of injection moldings in a cavity in a mold of an injection-molding machine after the operation of filling this cavity with a molten material has ended, with the temperature of the mold being controlled, and to a device used for this purpose.

In known methods used to fill a mold for example with thermoplastics, the filling operation is controlled in such a way that an initial speed-managed phase is followed by a pressure-managed phase which lasts until the end of the filling operation. Toward the end of the speed-managed phase or in the starting section of the pressure-managed phase, the filling situation in which the impression is completely wetted with plasticizable material is reached yet the pressure of the material in the interior of the impression is still relatively low. On account of the continuing movement of an injection plunger or an extruder, the internal pressure in the mold rises, which is associated with a reduction in the specific volume or an increase in the density of the molding material inside the impression. The extent of compression which can be achieved in this way is dependent both on the prevailing temperature and on the level of the pressure which is active and on the characteristic properties of the molding material.

After the supply of molten material to the impression has stopped, the molten material in the gate starts to solidify. This seals the impression, making it impossible for any further molten plastic to be supplied. The temperature in the impression drops until the one-bar isochor is reached. The molding then begins to shrink until the molding has reached room temperature.

The shrinkage of the molding is determined by the pressure and temperature conditions and also in particular by the viscosity of the molten material in the cavity. A significant factor in the shrinkage of the molding is the temperature distribution in the cavity at the end of the filling phase (or from the pressure maximum) until the end of the cycle. A differing shrinkage from cycle to cycle results from the fluctuation of the temperature profile and from the fluctuation of the mold internal pressure profile.

This applies both to single molds and to multi-impression molds. When producing injection moldings of all types (plastic, metal, ceramic, etc), for cost reasons it is often the case that a plurality of moldings are produced simultaneously each cycle (multi-impression mold). In this case, the individual cavities are normally balanced with regard to geometry and gate points to a sufficient extent for the quality of the injection moldings to be as uniform as possible. In reality, however, the shrinkage of the individual injection moldings is always different, and also changes constantly, on account of material fluctuations, temperature fluctuations and resulting fluctuations in viscosity.

It is an object of the present invention to provide a simple method which enables the shrinkage of the molding to be made as uniform as possible both between individual cavities of a multi-impression mold and also from cycle to cycle of an injection-molding operation.

SUMMARY OF THE INVENTION

The foregoing object is achieved by virtue of the fact that the temperature and/or an internal pressure in the cavity is monitored and is matched to a reference profile by controlling the temperature of the mold from the end of the filling phase or from a pressure maximum in the cavity until the end of the injection cycle.

Matching the current temperature or mold internal pressure profile to a reference profile from the end of the filling phase until the end of the cycle keeps the shrinkage of the injection molding constant. The same also applies to a multi-impression mold in which the temperature or mold internal pressure profiles of the individual cavities are monitored and controlled individually from the end of the filling phase until the end of the cycle.

To ensure uniform shrinkage, atmospheric pressure must be reached at the same mold wall temperature. To determine atmospheric pressure, the mold internal pressure is measured and at the same time the mold temperature is determined. In this way, by suitable control, it is possible to achieve the same level of shrinkage given the same physical conditions.

Since the mold internal pressure decreases continuously along the length of the flow path on account of the viscosity of the structure, it has proven advisable for a mold internal pressure sensor to be positioned close to the gate in order to obtain as much information as possible. However, this is not imperative and could even be disadvantageous in the event of what is known as a residual pressure, i.e. in the event of atmospheric pressure not being reached on account of mold deformation.

Contrary to earlier assumptions, with regard to the arrangement of the temperature sensor it has emerged that the measurement corresponding to the internal pressure does not have to take place at precisely the same location, but rather, to simplify matters, the temperature sensor can be installed in the region of the temperature-control circuit in question. It is preferably arranged at the end of the flow path, since the temperature sensor can also fulfill further objectives at this point.

In the case of large-area moldings, a relatively large cavity is required. Therefore, it must be assumed that a plurality of temperature-control circuits are distributed over the flow path. To control shrinkage, a temperature sensor must be positioned in the region of the same temperature-control circuit in which the mold internal pressure sensor is also located. In addition, it is possible for a temperature sensor and optionally a pressure sensor to be installed in each further region of a temperature-control circuit all the way to the end of the flow path, with the aid of which the shrinkage is controlled in these regions too. The time at which the various temperatures are controlled is determined by the mold internal pressure when atmospheric pressure is reached. The temperature of the temperature-control medium is adjusted until the profile of the mold internal pressure from the maximum until atmospheric pressure is reached, on the one hand, and the profile of the mold temperature from the maximum until the value corresponding to atmospheric pressure, on the other hand, correspond to a predetermined reference value (good-quality molding).

In a preferred exemplary embodiment of the invention, the two parameters are not compared with one another on a time basis, but rather are plotted against one another, so that absolute correspondence results in a 45° straight line.

The control itself takes place completely independently of the injection-molding machine and affects only the temperature-control system of the mold.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages, features and details of the invention will emerge from the following description of preferred exemplary embodiments and with reference to the drawing, in which:

FIG. 1 shows a diagrammatically depicted cross section through an injection mold;

FIG. 2 a and FIG. 2 b show diagrams illustrating the pressure profile and temperature profile while a cavity is being filled;

FIG. 3 diagrammatically depicts cavities of a multi-impression injection mold;

FIG. 4 diagrammatically depicts a cavity of an injection mold for large-area moldings;

FIGS. 5 a and 5 b show diagrams illustrating the pressure drop during shrinkage of an injection molding in a cavity.

DETAILED DESCRIPTION

FIG. 1 illustrates a closed injection mold 1. It substantially comprises two mold plates 2 and 3, with cores 4, which in the closed position engage in cavities 5 in the mold plate 2, projecting from the mold plate 3. Cores 4 and cavities 5 together in each case form an impression 6 which, by way of example, may be filled by a molten plastic. This plastic is passed through a hot runner 7 of a nozzle 8 and injected into the impression 6 at a gate 9.

According to the invention, it is preferable for each cavity 5 to be assigned at least one temperature sensor 10. This temperature sensor 10 is located at the end of the filling path of the cavity 5, preferably at approximately 95-98% of the filling path of the cavity. Furthermore, the cavity 5 is assigned a pressure sensor 20 which is provided in the vicinity of the gate 9.

In the nozzles 8 there are heating passages 11, by means of which a molten plastic in the hot runner 7 is held at a desired temperature. By contrast, in the mold plate 2, in the region of the cavities 5, there are cooling passages 12, which in turn bring the plastic in the impression 6 to a desired temperature, so that it solidifies there after a desired period of time and the molded article can be removed from the cavity 5.

It can be seen from FIG. 2 a that when the cavity 5 is being filled with molten material, the pressure rises very quickly up to a maximum 13 then drops more slowly until a sealing point 14 at which the gate is closed.

The pressure then drops further to 1 bar and ultimately a temperature of 200 Celsius is reached.

If in particular the sequence of events after the filling operation has ended is plotted against temperature in accordance with FIG. 2 b, the pressure maximum can be seen at 13. The temperature then drops to the sealing point 14 and then to the 1-bar isochor 15, with the shrinkage of the molding now commencing. The molding shrinks in the area a until the temperature of 20° Celsius is reached. Then, the molding is removed from the cavity 5.

The way in which the present invention functions is explained with reference to FIGS. 3 to 5 b.

FIG. 3 diagrammatically depicts a multi-impression mold. Each individual cavity 5 is assigned a dedicated temperature-control circuit 16 which, by way of example, includes the cooling passages 12. Furthermore, each cavity 5 is assigned a pressure sensor 20 and a temperature sensor 10.

The temperature sensor 10 monitors the temperature in the cavity 5, while the internal pressure in the cavity 5 is determined by the pressure sensor 20. The corresponding measurement of the two parameters does not have to take place exactly at the same location, but rather, to simplify matters, may take place in the region of the corresponding temperature-control circuit 16. Each individual temperature-control circuit 16 is controlled by adjusting the temperature of the temperature-control medium until the profile of the mold internal pressure from the maximum until atmospheric pressure is reached, on the one hand, and the profile of the mold temperature from the maximum to a value corresponding to atmospheric pressure, on the other hand, corresponds to a predetermined reference value.

In accordance with FIG. 5 b, the two parameters are not compared with one another on a time basis, but rather are plotted against one another, so that in the case of absolute correspondence a 45° straight line is shown. This form of presentation is preferred, although FIG. 5 a also illustrates the pressure profile after filling against time.

In the case of a mold in which large-area moldings are produced, the cavity 5.1 is significantly enlarged. Therefore, a cavity 5.1 of this type also has a plurality of gates 9.1 to 9.5, with at least the gate 9.1 also being assigned a pressure sensor 20. Of course, depending on the particular requirements, it is also possible for the other gates 9.2 to 9.5 to each be assigned a pressure sensor 20. However, this is not imperative.

Furthermore, the cavity 5.1 has a plurality of temperature-control circuits 16 and a plurality of temperature sensors 10.

Control is effected in the manner described above.

Claims (3)

1. A method for controlling the shrinkage of injection moldings in a cavity in a mold of an injection-molding machine after the operation of filling the cavity with a molten material has ended, comprising positioning a temperature sensor and a pressure sensor in a mold cavity, monitoring the temperature of and internal pressure in the mold cavity with the temperature sensor and the pressure sensor, respectively, continuously from the end of the filling phase or from a pressure maximum in the mold cavity until the end of the injection cycle matching the monitored temperature and internal pressure to a reference profile by controlling the temperature of the mold from the end of the filling phase or from a pressure maximum in the cavity until the end of the injection cycle, wherein the mold temperature is controlled so that atmospheric pressure is always reached at the same mold temperature.
2. The method as claimed in claim 1, wherein the monitored temperature and/or pressure profile is plotted against the respective reference profile.
3. The method as claimed in claim 1, wherein the pressure sensor is positioned close to a gate and the temperature sensor is positioned toward the end of the flow path of the molten material.
US10/472,861 2001-03-22 2002-03-14 Method for regulating the contraction of molded parts Active 2022-06-11 US7431871B2 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
DE2001114228 DE10114228A1 (en) 2001-03-22 2001-03-22 Method for controlling the shrinkage of injection parts
DE10114228.5 2001-03-22
PCT/EP2002/002844 WO2002076704A1 (en) 2001-03-22 2002-03-14 Method for regulating the contraction of molded parts

Publications (2)

Publication Number Publication Date
US20040131715A1 US20040131715A1 (en) 2004-07-08
US7431871B2 true US7431871B2 (en) 2008-10-07

Family

ID=7678678

Family Applications (1)

Application Number Title Priority Date Filing Date
US10/472,861 Active 2022-06-11 US7431871B2 (en) 2001-03-22 2002-03-14 Method for regulating the contraction of molded parts

Country Status (8)

Country Link
US (1) US7431871B2 (en)
EP (1) EP1377427B9 (en)
JP (1) JP4155826B2 (en)
DE (2) DE10114228A1 (en)
DK (1) DK1377427T5 (en)
ES (1) ES2330416T3 (en)
PT (1) PT1377427E (en)
WO (1) WO2002076704A1 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110151041A1 (en) * 2009-12-23 2011-06-23 Groleau Rodney J Method for installing indirect and direct mold pressure, temperature and flow front detection sensors without machining the mold
US8980146B2 (en) 2013-08-01 2015-03-17 Imflux, Inc. Injection molding machines and methods for accounting for changes in material properties during injection molding runs
US9475226B2 (en) 2013-08-01 2016-10-25 Imflux Inc Injection molding machines and methods for accounting for changes in material properties during injection molding runs
US9643351B2 (en) 2013-08-01 2017-05-09 Imflux Inc Injection molding machines and methods for accounting for changes in material properties during injection molding runs

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10258100B4 (en) * 2002-12-11 2005-12-01 Priamus System Technologies Ag A method of manufacturing a device for measuring, monitoring and / or controlling a temperature
DE10261498B4 (en) * 2002-12-23 2008-04-30 Priamus System Technologies Ag A method for controlling the production of molded parts
DE102004026394A1 (en) * 2004-05-29 2005-12-22 Müller Weingarten AG Optimizing control of dwell pressure- and solidification interval in die casting machines, measures temperature as control magnitude to end each phase
DE102004043443B3 (en) 2004-09-06 2006-02-02 Priamus System Technologies Ag An apparatus for molding articles
DE102005029705A1 (en) * 2005-06-10 2006-12-14 Priamus System Technologies Ag A method of controlling an injection molding machine Spritzgiesprozesses
DE102006050382A1 (en) * 2006-10-25 2008-04-30 Bayer Materialscience Ag High-pressure injection molding method for producing optical components
DE102007029977B4 (en) * 2007-06-28 2009-09-24 Sumitomo (Shi) Demag Plastics Machinery Gmbh A method for carrying out the decomposition at a clamping force of the clamping unit of an injection molding
DE102009027646A1 (en) 2009-07-13 2011-01-20 Evonik Röhm Gmbh Apparatus and method for producing thick-walled plastic moldings with reduced sink marks by injection molding or -prägen
EP2485881B1 (en) 2009-10-05 2013-12-11 Priamus System Technologies AG Method for controlling the production of a product
DE102009057054B4 (en) * 2009-12-04 2011-07-14 Audi Ag, 85057 Tools and methods for treating temperature of a cast component
DE102009060665A1 (en) 2009-12-22 2011-06-30 Priamus System Technologies Ag Method for controlling e.g. cavity pressure of product, to control production of product in injection molding machine, involves modifying shear rate and/or shear stress until product reaches desired quality
AT514847B1 (en) * 2013-09-30 2015-06-15 Engel Austria Gmbh A method for determining a desired value for a setting parameter
DE102016123495A1 (en) * 2016-12-05 2018-06-07 Schuler Pressen Gmbh Tool for molding and / or forming a component, the casting apparatus, the press and method of gap compensation

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3941534A (en) * 1971-11-01 1976-03-02 Hunkar Laboratories, Inc. Injection molding control system
US4615849A (en) * 1982-11-25 1986-10-07 Sodemape Holding Ag Method and device for sintering differing molded parts in particular from various types of foaming plastic in particular
US4623497A (en) * 1984-11-28 1986-11-18 Application Engineering Corporation Passive mold cooling and heating method
US4671696A (en) * 1984-08-27 1987-06-09 Hitachi, Ltd. Shaft assembly and manufacturing process thereof
US4850217A (en) * 1988-04-12 1989-07-25 Hpm Corporation Adaptive process control for injection molding
US4983336A (en) * 1987-11-07 1991-01-08 U.S. Philips Corporation Method of controlling the afterpressure variation with time of an injection-moulding machine
US5296174A (en) * 1991-03-19 1994-03-22 Japan Steel Works Co., Ltd. Method of controlling holding pressure in injection molding and apparatus therefor
US5427720A (en) * 1993-03-09 1995-06-27 Kotzab; Werner Method for mold temperature control
US5720912A (en) * 1994-09-27 1998-02-24 Kunststofftechnik F. U. H. Riesselmann Gmbh Method for controlling the temperature of an injection-molding machine and mold tool units
US5772933A (en) * 1994-10-12 1998-06-30 Kotzab; Werner Method for tempering an injection mold having at least one heated nozzle or hot runner
US6500368B1 (en) * 1999-12-29 2002-12-31 Kaneka Corporation Polyolefin synthetic resin in-mold foam molding method

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6330131B2 (en) * 1979-12-12 1988-06-16 Toyoda Chuo Kenkyusho Kk
DE3608973C2 (en) * 1986-03-18 1997-01-23 Peter Prof Dipl Ing Wippenbeck Method and apparatus for controlling switching of the emphasis in the isochoric cooling phase phase during the injection molding of thermoplastics
DE4026731A1 (en) * 1990-08-24 1992-02-27 Peter Prof Dipl Ing Wippenbeck Computer controlled injection moulding to maintain isochore phase - by monitoring pressure and temp. valves against time and determining representing core of shot by computer

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3941534A (en) * 1971-11-01 1976-03-02 Hunkar Laboratories, Inc. Injection molding control system
US4615849A (en) * 1982-11-25 1986-10-07 Sodemape Holding Ag Method and device for sintering differing molded parts in particular from various types of foaming plastic in particular
US4671696A (en) * 1984-08-27 1987-06-09 Hitachi, Ltd. Shaft assembly and manufacturing process thereof
US4623497A (en) * 1984-11-28 1986-11-18 Application Engineering Corporation Passive mold cooling and heating method
US4983336A (en) * 1987-11-07 1991-01-08 U.S. Philips Corporation Method of controlling the afterpressure variation with time of an injection-moulding machine
US4850217A (en) * 1988-04-12 1989-07-25 Hpm Corporation Adaptive process control for injection molding
US5296174A (en) * 1991-03-19 1994-03-22 Japan Steel Works Co., Ltd. Method of controlling holding pressure in injection molding and apparatus therefor
US5427720A (en) * 1993-03-09 1995-06-27 Kotzab; Werner Method for mold temperature control
US5427720C1 (en) * 1993-03-09 2001-01-30 Werner Kotzab Method for mold temperature control
US5720912A (en) * 1994-09-27 1998-02-24 Kunststofftechnik F. U. H. Riesselmann Gmbh Method for controlling the temperature of an injection-molding machine and mold tool units
US5772933A (en) * 1994-10-12 1998-06-30 Kotzab; Werner Method for tempering an injection mold having at least one heated nozzle or hot runner
US6500368B1 (en) * 1999-12-29 2002-12-31 Kaneka Corporation Polyolefin synthetic resin in-mold foam molding method

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110151041A1 (en) * 2009-12-23 2011-06-23 Groleau Rodney J Method for installing indirect and direct mold pressure, temperature and flow front detection sensors without machining the mold
US8425217B2 (en) 2009-12-23 2013-04-23 Rodney J. Groleau Method for installing indirect and direct mold pressure, temperature and flow front detection sensors without machining the mold
US8980146B2 (en) 2013-08-01 2015-03-17 Imflux, Inc. Injection molding machines and methods for accounting for changes in material properties during injection molding runs
US9321206B2 (en) 2013-08-01 2016-04-26 Imflux, Inc. Injection molding machines and methods for accounting for changes in material properties during injection molding runs
US9475226B2 (en) 2013-08-01 2016-10-25 Imflux Inc Injection molding machines and methods for accounting for changes in material properties during injection molding runs
US9481119B2 (en) 2013-08-01 2016-11-01 iMFLUX Inc. Injection molding machines and methods for accounting for changes in material properties during injection molding runs
US9643351B2 (en) 2013-08-01 2017-05-09 Imflux Inc Injection molding machines and methods for accounting for changes in material properties during injection molding runs

Also Published As

Publication number Publication date
DK1377427T3 (en) 2009-10-19
EP1377427B1 (en) 2009-07-22
US20040131715A1 (en) 2004-07-08
DE50213698D1 (en) 2009-09-03
JP4155826B2 (en) 2008-09-24
JP2004525794A (en) 2004-08-26
DE10114228A1 (en) 2002-10-02
EP1377427B9 (en) 2010-02-17
DK1377427T5 (en) 2010-01-04
PT1377427E (en) 2009-10-12
WO2002076704A1 (en) 2002-10-03
ES2330416T3 (en) 2009-12-10
EP1377427A1 (en) 2004-01-07

Similar Documents

Publication Publication Date Title
CN1104322C (en) Injection molding system with sequential gate control
US4685881A (en) Nozzle assembly for injection molding
JP2918211B2 (en) Press-molding method and molding apparatus
EP0442255B1 (en) Molding plastic articles
EP0758292B1 (en) Method and apparatus for injection molding
US5470219A (en) Runnerless injection molding of synthetic resin with a valve gate
US5192555A (en) Apparatus for molding plastic articles
EP0309182B2 (en) Method for injection molding
US5427720A (en) Method for mold temperature control
US4917840A (en) Mold compression control process for an injection molding machine and apparatus thereof
CA1085125A (en) Injection molding machine and method
US4208176A (en) Time independent cycle control for plastic injection molding machines
US3932083A (en) Injection molding control
US4701292A (en) Method for pressure molding objects of different resins
US4932854A (en) Apparatus for control of injection molding machine
CN1162266C (en) Plastic products forming method
US5591385A (en) Method for cooling injection molding molds
US4855094A (en) Method for the injection molding of plastic articles using fluid pressure
US4318874A (en) Molding apparatus
EP0389646B1 (en) Process and apparatus for injection molding
US5260012A (en) Molding plastic articles
US5773038A (en) Apparatus for family mold sequential molding
CN1296440A (en) Automated molding technology for thermoplastic injection molding
EP0640460B1 (en) Method for producing a thin film
JP3169382B2 (en) Injection molding of thermoplastic polymers

Legal Events

Date Code Title Description
AS Assignment

Owner name: PRIAMUS SYSTEM TECHNOLOGIES AG, SWITZERLAND

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:FREY, JURGEN;REEL/FRAME:014896/0320

Effective date: 20030903

STCF Information on status: patent grant

Free format text: PATENTED CASE

FPAY Fee payment

Year of fee payment: 4

FPAY Fee payment

Year of fee payment: 8